Relative chlorophyll contents in the evaluation of the nutritional status of nitrogen from xaraes palisade grass and determination of critical nitrogen sufficiency index
The nutritional status of xaraes palisade grass with SPAD chlorophyll meter and the critical nitrogen sufficiency index (cNSI) in the dry and rainy seasons were assessed. The experiment was conducted in a completely randomized design with four treatments (50, 100, 200 and 400 kg N ha-1), three repli...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | Brasil |
| Institución: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/213179 |
| Acceso en línea: | http://dx.doi.org/10.4025/actascianimsci.v37i2.24854 http://hdl.handle.net/11449/213179 |
| Access Level: | acceso abierto |
| Palabra clave: | fertilization: Urochloa brizantha chlorophyll meter: nutritional status: SPAD. adubação Urochloa brizantha clorofilômetro estado nutricional SPAD |
| Sumario: | The nutritional status of xaraes palisade grass with SPAD chlorophyll meter and the critical nitrogen sufficiency index (cNSI) in the dry and rainy seasons were assessed. The experiment was conducted in a completely randomized design with four treatments (50, 100, 200 and 400 kg N ha-1), three replicates and two seasons: dry and rainy. All variables had a high nonlinear relationship with their predictors (p < 0.001). Total nitrogen (TN) reached a plateau at doses 262.0 and 514.8 kg of N ha-1 and the concentration of TN in the plant was 1.88 and 1.93% respectively during the rainy and dry season. Relative chlorophyll content (RCC) reached a plateau at 46.05 and 53.65 SPAD units in the rainy and dry seasons, respectively. The production of dry matter (DM) showed maximum response to nitrogen fertilization at 209.5 and 229.1 kg N ha-1 during the rainy and dry season respectively. The nitrogen sufficiency index (NSI) reached the plateau at 0.85 and 0.99 in the rainy and dry season respectively. All variables showed high linear correlation (r = 0.71 to 0.99). The xaraés palisade grass's cNSI is 0.85 and the chlorophyll meter may be used as a nutritional N management tool for the grass. |
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